Since power generation using renewable energy such as wind power generation and solar power generation depends on weather conditions, the output may not be stable. For this reason, it is necessary to level the output by using an energy storage system such as a compressed air energy storage (CAES) system.
It is common that the conventional compressed air energy storage (CAES) power generation device stores electric energy as compressed air in the accumulator tank during the off-peak time of the power plant, and drives the expander with the compressed air to operate the generator to generate electrical energy during the high power demand time.
In addition, in order to improve power generation efficiency, there is one that performs heat recovery on the compression heat of the compressed air to store heat in the heat storage tank or the like to return heat to the compressed air before expansion, whereby prevents heat energy loss by dissipating heat in the accumulator tank.
As this CAES power generation device, for example, JP 2013-509530 a discloses a CAES power generation device using a heat energy storage system.
However, if manufactured in a size corresponding to the accumulation amount at the time of the peak of the high power demand, the accumulator tank that stores compressed air needs to be large size. Therefore, much equipment cost is needed.